Struct frame_support::storage::types::OptionQuery[−][src]

pub struct OptionQuery;

Expand description

Implement QueryKindTrait with query being Option<Value>

NOTE: it doesn’t support a generic OnEmpty. This means only None can be returned when no value is found. To use another OnEmpty implementation, ValueQuery can be used instead.

Trait Implementations

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impl<Value> QueryKindTrait<Value, GetDefault> for OptionQuery where
    Value: FullCodec + 'static,

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const METADATA: StorageEntryModifier

Metadata for the storage kind.

type Query = Option<Value>

Type returned on query

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fn from_optional_value_to_query(v: Option<Value>) -> Self::Query

Convert an optional value (i.e. some if trie contains the value or none otherwise) to the query. Read more

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fn from_query_to_optional_value(v: Self::Query) -> Option<Value>

Convert a query to an optional value.

Auto Trait Implementations

impl RefUnwindSafe for OptionQuery

impl Send for OptionQuery

impl Sync for OptionQuery

impl Unpin for OptionQuery

impl UnwindSafe for OptionQuery

Blanket Implementations

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impl<T> Any for T where
    T: 'static + ?Sized,

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pub fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T where
    T: ?Sized,

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pub fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T where
    T: ?Sized,

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pub fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> CheckedConversion for T

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fn checked_from<T>(t: T) -> Option<Self> where
    Self: TryFrom<T>,

Convert from a value of T into an equivalent instance of Option<Self>. Read more

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fn checked_into<T>(self) -> Option<T> where
    Self: TryInto<T>,

Consume self to return Some equivalent value of Option<T>. Read more

impl<T> Downcast for T where
    T: Any,

pub fn into_any(self: Box<T, Global>) -> Box<dyn Any + 'static, Global>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait. Read more

pub fn into_any_rc(self: Rc<T>) -> Rc<dyn Any + 'static>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait. Read more

pub fn as_any(&self) -> &(dyn Any + 'static)

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s. Read more

pub fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s. Read more

impl<T> DowncastSync for T where
    T: Any + Send + Sync,

pub fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Sync + Send + 'static>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait. Read more

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impl<T> From<T> for T

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pub fn from(t: T) -> T

Performs the conversion.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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impl<T, U> Into<U> for T where
    U: From<T>,

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pub fn into(self) -> U

Performs the conversion.

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impl<T, Outer> IsWrappedBy<Outer> for T where
    T: From<Outer>,
    Outer: AsRef<T> + AsMut<T> + From<T>,

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pub fn from_ref(outer: &Outer) -> &T

Get a reference to the inner from the outer.

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pub fn from_mut(outer: &mut Outer) -> &mut T

Get a mutable reference to the inner from the outer.

impl<T> Same<T> for T

type Output = T

Should always be Self

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impl<T> SaturatedConversion for T

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fn saturated_from<T>(t: T) -> Self where
    Self: UniqueSaturatedFrom<T>,

Convert from a value of T into an equivalent instance of Self. Read more

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fn saturated_into<T>(self) -> T where
    Self: UniqueSaturatedInto<T>,

Consume self to return an equivalent value of T. Read more

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impl<T, U> TryFrom<U> for T where
    U: Into<T>,

type Error = Infallible

The type returned in the event of a conversion error.

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pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

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impl<T, U> TryInto<U> for T where
    U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

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pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

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impl<S, T> UncheckedInto<T> for S where
    T: UncheckedFrom<S>,

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pub fn unchecked_into(self) -> T

The counterpart to unchecked_from.

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impl<T, S> UniqueSaturatedInto<T> for S where
    T: Bounded,
    S: TryInto<T>,

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pub fn unique_saturated_into(self) -> T

Consume self to return an equivalent value of T.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>,

pub fn vzip(self) -> V

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impl<T> MaybeRefUnwindSafe for T where
    T: RefUnwindSafe,